Plants have traditionally been one of man's richest sources of biologically active materials; over 25% of all prescriptions dispensed in the U.S. contain a plant derived active principle. In collaboration with the University of Illinois at Chicago and Research Triangle Institute, Bristol-Myers Squibb plans to identify, isolate and characterize novel plant derived anticancer agents. Bristol-Myers Squibb Pharmaceutical Research Institute is a part of one of the largest pharmaceutical companies in the world with a strong commitment and resources dedicated to natural products screening. With respect to the NCNPDDG in question, we plan to carry out the following specific aims. 1. To assay ca. 500 plant samples per year for cytotoxicity, interaction with specific oncogenes, enzymes and proteins of DNA metabolism. 2. To assist in selecting and prioritizing the most biologically significant leads. 3 To support bioassay-guided fractionation of the active constituents. 4. To participate in the isolation and structure elucidation of the active constituents. 5. To obtain sufficient amounts of active compounds, by extraction and purification or by partial or total synthesis, depending upon the complexity of the molecule in question. 6. To profile in vitro and in vivo the biological properties of lead compounds obtained from this program. 7. To carry out the large-scale isolation and/or synthesis and the preclinical drug development of lead candidates. Bristol-Myers Squibb has an outstanding track record in accomplishing this type of aim, having successfully brought to clinical trials over five anticancer agents in the past six to seven years and having successfully solved the taxol supply problem.